I was having a problem in Fx29 where I would enter customization mode but not be able to exit it. Clicking the Exit Customize button at the bottom of the simulated menupanel would do nothing (other than throw errors, see below). To get out of customization, I had to close the tab holding the customization screen and restart the browser.

It turned out I was using the wrong binding on #nav-bar, which was breaking customization. I was using

also: - [1] #titlebar simply doesn't exist in DOM for linux, period - [2] it has the [customizable] attribute, but to actually drag items on/off of it, it can't be autohidden, else it stays hidden during customization - option to pick visible toolbars during customization: yes - option to show/hide titlebar during customization: no

also: - [1] #titlebar hidden when no persona with display: none from content/browser.css - [2] #titlebar not hidden when using a persona, and has height and width, but carries no visible styling (it's fully transparent) - [3] menubar not actually shown in browser ui; this DOM is reinterpreted into the desktop menubar - [4] menubar is probably never autohide on osx (desktop menubar instead) - option to pick visible toolbars during customization: no - option to show/hide titlebar during customization: yes

also: - [1] it has the [customizable] attribute, but to actually drag items on/off of it, it can't be autohidden, else it stays hidden during customization - option to pick visible toolbars during customization: yes - option to show/hide titlebar during customization: yes